Step 1: Open Terminal ( Applications —-> Accessories —–> Terminal or Ctrl + Alt + T)
Step 2: Edit the /etc/lightdm/lightdm.conf file.
raj@geeksite~$ sudo gedit /etc/lightdm/lightdm.conf
Step 3: Add the following line at the end of the above file.
greeter-hide-users=true
Step 4: Reboot
raj@geeksite~$ sudo reboot
Now the login scree will look like below without User Names list except Guest Session.
That’s all.